Well, looking at this thread, on my device (hence without caching), all pictures in (your) postings #1, #2 and #4 are embedded fine (i.e., also at the correct places within each posting). In contrast to that the pictures in the postings #8 and #9 are correctly placed but not displayed, and trying to open them manually (Context menu: View image) results in opening a TMO page stating: vBulletin Message Invalid Attachment specified. If you followed a valid link, please notify the administrator
It looks like there is at least one way to embed pictures anywhere in a message, plus a way to attach pictures at the bottom of a message.